Discount configuration how?

I want to setup discount so when buyer adds products for certain amount say 100$ to cart he receives 10% discount on order + free shipping. Now I know how to do this but problem is I have “Sale” category were I offer lowest price possible and I wish not to go any lower with such discount running.

I can setup this discount so it is enabled if products are not in sale category, but in such case if at least one product is from sale category discount coupon is not accepted at all.

I wish 10% would be deducted from all product excluding my “sale” category.

Please advice if anyone knows solution.

In settings there is checkbox

“If discount coupon is used, don’t apply other discounts”

I have this on.

Conditions are 3 products more then 100$ total get 10% off

One of them is already with 9% off (listing price is higher then actual price).

But when discount coupon applied 10% discount is still deducted from item with discount already.

Is this a bug?